Device for after-treatment of exhaust gases from internal combustion engines

ABSTRACT

Ceramic support bodies for the after-treatment of exhaust gases of internal combustion engines is provided. On a jacket of the support body heat-resistant elevations are subsequently applied that fix the bed against movement.

This nonprovisional application claims priority under 35 U.S.C. § 119(a)to German Patent Application No. 20 2006 013 789, which was filed inGermany on Sep. 8, 2006, and which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to devices for the after-treatment ofexhaust gases from internal combustion engines.

2. Description of the Background Art

In exhaust gas catalysts or soot particle filters, which use a ceramicsupport body, are held in a housing with the aid of a bed mat. This bedmat has the task of balancing out the differences in thermal expansionof ceramic and metal as a result of the distinctly different expansioncoefficients. Special materials that expand upon heating are used as bedmats.

Nevertheless it is often observed in practice that the ceramic supportbody and/or the bed mat moves within the housing under the influence ofpulsating exhaust gases. This is unsatisfactory. Therefore, attemptshave been made to prevent these movements by means of terminal ringsmade of wire or sheet metal. Aside from the fact that these additionalmeasures represent an additional expense, they have not been successfulin practice.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a deviceso that movements of support bodies and/or bed mats relative to oneanother or to the housing can be reliably prevented.

Via elevations in accordance with an embodiment of the invention, theotherwise smooth jacket surface of the ceramic support body is modifiedto such an extent that a force-locking or form-locking connection takesplace between the support body and the bed mat. In this way, relativemovements of the two are prevented.

Advantageously, these elevations can include baked-on ceramic. These caneither already be placed on a green blank or subsequently applied to abaked blank, preferably using stencils.

According to an embodiment of the invention, these elevations areannular. In particular, two parallel rings can be recommended, betweenwhich the bed mat is fixed immovably and protected from the pulsations.

According to an alternative embodiment, the elevations can bepunctiform.

In this case it is advisable to incorporate into the bed mats recessesthat correspond to the elevations. In this manner it is possible toprevent the support body and bed mat from performing any furtherrelative movements with respect to one another.

To also rule out any relative movement between the housing and bed mator support body, according to a further embodiment of the invention, thehousing in turn may have recesses that correspond to the elevations onthe support body.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus, are not limitiveof the present invention, and wherein:

FIG. 1 illustrates a ceramic support body with annular elevations; and

FIG. 2 illustrates a support body with punctiform elevations.

DETAILED DESCRIPTION

FIG. 1 shows a first example embodiment. A ceramic support body 1 isrecognizable, with a plurality of honeycomb-like channels, which forexample are catalytically coated. On the jacket of the support body 1, abed mat 2 is wound. To reliably prevent relative movement between thesupport body 1 and bed mat 2 from occurring, two annular elevations 3are applied to the jacket of the support body 1. These have aheat-resistant material, especially baked-on ceramic, and fix the bedmat 2 in a form-locking way.

FIG. 2 shows an alternative exemplified embodiment. To the jacketsurface of the ceramic bed mat 1, punctiform elevations made of ceramicare applied. The corresponding bed mat 2 has recesses 5, whichcorrespond with the punctiform elevations 4. In this way, a form-lockingconnection is formed between the support body 1, elevations 4 and bedmat 2 or recesses 5, preventing relative movement.

To also prevent relative movement between the support body 1 and bed mat2 on one hand, and the catalyst housing (not shown) on the other, thehousing may be equipped in an area of its jacket with recesses thatcorrespond to the elevations 3, 4. Catalyst housings withcircumferential fins, which fit with the annular elevations 3 can beused without modification.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are to beincluded within the scope of the following claims.

1. A device for aftertreatment of exhaust gases of internal combustionengines, the comprising: an active ceramic support body; a bed mat; anda housing; wherein a jacket of the support body hastemperature-resistant elevations that are subsequently applied.
 2. Thedevice according to claim 1, wherein the elevations have a baked-onceramic.
 3. The device according to claim 1, wherein the elevations areannular.
 4. The device according to claim 1, wherein the elevations arepunctiform.
 5. The device according to claim 4, wherein the bed mat hasrecesses that correspond with the elevations.
 6. The device according toclaim 1, wherein the housing has recesses that correspond with theelevations.
 7. A device for treating exhaust gases of a vehicle, thedevice comprising: a ceramic support body having a plurality ofhoneycomb-shaped channels formed therein; a bed mat substantiallycircumscribing the ceramic support body; and a plurality of engagementdevices provided on the ceramic support body for fixedly supporting thebed mat to an outer surface of the ceramic support body, therebypreventing movement between the bed mat and the ceramic support body. 8.The device according to claim 7, wherein the engagement devices arepunctiform elevations that are provided on the ceramic support body suchthat the punctifom elevations correspond to a plurality of aperturesprovided in the bed mat for fixedly supporting the bed mat.